78340778397 has 64 divisors (see below), whose sum is σ = 140249088000. Its totient is φ = 42219434304.

The previous prime is 78340778393. The next prime is 78340778407. The reversal of 78340778397 is 79387704387.

78340778397 is a `hidden beast` number, since 78 + 3 + 407 + 78 + 3 + 97 = 666.

It is not a de Polignac number, because 78340778397 - 2² = 78340778393 is a prime.

It is a super-2 number, since 2×78340778397² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78340778393) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 751879 + ... + 849707.

It is an arithmetic number, because the mean of its divisors is an integer number (2191392000).

Almost surely, 2^78340778397 is an apocalyptic number.

It is an amenable number.

78340778397 is a deficient number, since it is larger than the sum of its proper divisors (61908309603).

78340778397 is a wasteful number, since it uses less digits than its factorization.

78340778397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98087 (or 98081 counting only the distinct ones).

The product of its (nonzero) digits is 49787136, while the sum is 63.

The spelling of 78340778397 in words is "seventy-eight billion, three hundred forty million, seven hundred seventy-eight thousand, three hundred ninety-seven".